In these days, researches and developments have been vigorously made on various indication elements. Among all, organic electroluminescence (EL) elements have attracted public attention as highly useful indication elements because of being capable of giving luminescence at a high luminance under a low voltage. For example, there have been known EL elements in which an organic thin film is formed by the vapor deposition of an organic compound (Applied Physics Letters, 51, from p. 913, (1987)). The organic EL elements reported in this document have a laminated structure made of an electron transport material and a hole transport material and show largely improved light-emitting (organic electroluminescent) characteristics compared with the conventional single-layered elements.
In such a layered element, the element is constructed by the vapor deposition of a low-molecular weight organic material as an element material. As a technique for forming a thin film as employed in organic EL elements, use can be made of various methods such as the vapor deposition method as described in the above document, the sputtering method, CVD, PVD and the coating method with the use of coating materials. These methods are described in detail in some publications such as ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES (OPA, Amsterdam, 1997) and Yuki EL Soshi to Sono Kogyoka Saizensen (NTS, 1998). The present inventors have studied on a method of coating solutions of organic compounds, in particular, organic polymer materials. Organic polymer materials are characterized by capable of forming thin films with little defects as a single material and the thus formed films being excellent in physical and chemical fastness. However, it has been found out that materials obtained merely by polymerizing luminous element materials suffer from problems in light-emitting performance and durability.